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| -rw-r--r-- | lib/queue.h | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/lib/queue.h b/lib/queue.h new file mode 100644 index 00000000..70cffab1 --- /dev/null +++ b/lib/queue.h @@ -0,0 +1,637 @@ +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)queue.h 8.5 (Berkeley) 8/20/94 + * $FreeBSD$ + */ + +#ifndef _SYS_QUEUE_H_ +#define _SYS_QUEUE_H_ + +#include <sys/cdefs.h> + +/* + * This file defines four types of data structures: singly-linked lists, + * singly-linked tail queues, lists and tail queues. + * + * A singly-linked list is headed by a single forward pointer. The elements + * are singly linked for minimum space and pointer manipulation overhead at + * the expense of O(n) removal for arbitrary elements. New elements can be + * added to the list after an existing element or at the head of the list. + * Elements being removed from the head of the list should use the explicit + * macro for this purpose for optimum efficiency. A singly-linked list may + * only be traversed in the forward direction. Singly-linked lists are ideal + * for applications with large datasets and few or no removals or for + * implementing a LIFO queue. + * + * A singly-linked tail queue is headed by a pair of pointers, one to the + * head of the list and the other to the tail of the list. The elements are + * singly linked for minimum space and pointer manipulation overhead at the + * expense of O(n) removal for arbitrary elements. New elements can be added + * to the list after an existing element, at the head of the list, or at the + * end of the list. Elements being removed from the head of the tail queue + * should use the explicit macro for this purpose for optimum efficiency. + * A singly-linked tail queue may only be traversed in the forward direction. + * Singly-linked tail queues are ideal for applications with large datasets + * and few or no removals or for implementing a FIFO queue. + * + * A list is headed by a single forward pointer (or an array of forward + * pointers for a hash table header). The elements are doubly linked + * so that an arbitrary element can be removed without a need to + * traverse the list. New elements can be added to the list before + * or after an existing element or at the head of the list. A list + * may only be traversed in the forward direction. + * + * A tail queue is headed by a pair of pointers, one to the head of the + * list and the other to the tail of the list. The elements are doubly + * linked so that an arbitrary element can be removed without a need to + * traverse the list. New elements can be added to the list before or + * after an existing element, at the head of the list, or at the end of + * the list. A tail queue may be traversed in either direction. + * + * For details on the use of these macros, see the queue(3) manual page. + * + * + * SLIST LIST STAILQ TAILQ + * _HEAD + + + + + * _HEAD_INITIALIZER + + + + + * _ENTRY + + + + + * _INIT + + + + + * _EMPTY + + + + + * _FIRST + + + + + * _NEXT + + + + + * _PREV - - - + + * _LAST - - + + + * _FOREACH + + + + + * _FOREACH_SAFE + + + + + * _FOREACH_REVERSE - - - + + * _FOREACH_REVERSE_SAFE - - - + + * _INSERT_HEAD + + + + + * _INSERT_BEFORE - + - + + * _INSERT_AFTER + + + + + * _INSERT_TAIL - - + + + * _CONCAT - - + + + * _REMOVE_AFTER + - + - + * _REMOVE_HEAD + - + - + * _REMOVE + + + + + * _SWAP + + + + + * + */ +#ifdef QUEUE_MACRO_DEBUG +/* Store the last 2 places the queue element or head was altered */ +struct qm_trace { + char * lastfile; + int lastline; + char * prevfile; + int prevline; +}; + +#define TRACEBUF struct qm_trace trace; +#define TRASHIT(x) do {(x) = (void *)-1;} while (0) +#define QMD_SAVELINK(name, link) void **name = (void *)&(link) + +#define QMD_TRACE_HEAD(head) do { \ + (head)->trace.prevline = (head)->trace.lastline; \ + (head)->trace.prevfile = (head)->trace.lastfile; \ + (head)->trace.lastline = __LINE__; \ + (head)->trace.lastfile = __FILE__; \ +} while (0) + +#define QMD_TRACE_ELEM(elem) do { \ + (elem)->trace.prevline = (elem)->trace.lastline; \ + (elem)->trace.prevfile = (elem)->trace.lastfile; \ + (elem)->trace.lastline = __LINE__; \ + (elem)->trace.lastfile = __FILE__; \ +} while (0) + +#else +#define QMD_TRACE_ELEM(elem) +#define QMD_TRACE_HEAD(head) +#define QMD_SAVELINK(name, link) +#define TRACEBUF +#define TRASHIT(x) +#endif /* QUEUE_MACRO_DEBUG */ + +/* + * Singly-linked List declarations. + */ +#define SLIST_HEAD(name, type) \ +struct name { \ + struct type *slh_first; /* first element */ \ +} + +#define SLIST_HEAD_INITIALIZER(head) \ + { NULL } + +#define SLIST_ENTRY(type) \ +struct { \ + struct type *sle_next; /* next element */ \ +} + +/* + * Singly-linked List functions. + */ +#define SLIST_EMPTY(head) ((head)->slh_first == NULL) + +#define SLIST_FIRST(head) ((head)->slh_first) + +#define SLIST_FOREACH(var, head, field) \ + for ((var) = SLIST_FIRST((head)); \ + (var); \ + (var) = SLIST_NEXT((var), field)) + +#define SLIST_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = SLIST_FIRST((head)); \ + (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ + (var) = (tvar)) + +#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ + for ((varp) = &SLIST_FIRST((head)); \ + ((var) = *(varp)) != NULL; \ + (varp) = &SLIST_NEXT((var), field)) + +#define SLIST_INIT(head) do { \ + SLIST_FIRST((head)) = NULL; \ +} while (0) + +#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ + SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ + SLIST_NEXT((slistelm), field) = (elm); \ +} while (0) + +#define SLIST_INSERT_HEAD(head, elm, field) do { \ + SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ + SLIST_FIRST((head)) = (elm); \ +} while (0) + +#define SLIST_NEXT(elm, field) ((elm)->field.sle_next) + +#define SLIST_REMOVE(head, elm, type, field) do { \ + QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ + if (SLIST_FIRST((head)) == (elm)) { \ + SLIST_REMOVE_HEAD((head), field); \ + } \ + else { \ + struct type *curelm = SLIST_FIRST((head)); \ + while (SLIST_NEXT(curelm, field) != (elm)) \ + curelm = SLIST_NEXT(curelm, field); \ + SLIST_REMOVE_AFTER(curelm, field); \ + } \ + TRASHIT(*oldnext); \ +} while (0) + +#define SLIST_REMOVE_AFTER(elm, field) do { \ + SLIST_NEXT(elm, field) = \ + SLIST_NEXT(SLIST_NEXT(elm, field), field); \ +} while (0) + +#define SLIST_REMOVE_HEAD(head, field) do { \ + SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ +} while (0) + +#define SLIST_SWAP(head1, head2, type) do { \ + struct type *swap_first = SLIST_FIRST(head1); \ + SLIST_FIRST(head1) = SLIST_FIRST(head2); \ + SLIST_FIRST(head2) = swap_first; \ +} while (0) + +/* + * Singly-linked Tail queue declarations. + */ +#define STAILQ_HEAD(name, type) \ +struct name { \ + struct type *stqh_first;/* first element */ \ + struct type **stqh_last;/* addr of last next element */ \ +} + +#define STAILQ_HEAD_INITIALIZER(head) \ + { NULL, &(head).stqh_first } + +#define STAILQ_ENTRY(type) \ +struct { \ + struct type *stqe_next; /* next element */ \ +} + +/* + * Singly-linked Tail queue functions. + */ +#define STAILQ_CONCAT(head1, head2) do { \ + if (!STAILQ_EMPTY((head2))) { \ + *(head1)->stqh_last = (head2)->stqh_first; \ + (head1)->stqh_last = (head2)->stqh_last; \ + STAILQ_INIT((head2)); \ + } \ +} while (0) + +#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) + +#define STAILQ_FIRST(head) ((head)->stqh_first) + +#define STAILQ_FOREACH(var, head, field) \ + for((var) = STAILQ_FIRST((head)); \ + (var); \ + (var) = STAILQ_NEXT((var), field)) + + +#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = STAILQ_FIRST((head)); \ + (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ + (var) = (tvar)) + +#define STAILQ_INIT(head) do { \ + STAILQ_FIRST((head)) = NULL; \ + (head)->stqh_last = &STAILQ_FIRST((head)); \ +} while (0) + +#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ + if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ + (head)->stqh_last = &STAILQ_NEXT((elm), field); \ + STAILQ_NEXT((tqelm), field) = (elm); \ +} while (0) + +#define STAILQ_INSERT_HEAD(head, elm, field) do { \ + if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ + (head)->stqh_last = &STAILQ_NEXT((elm), field); \ + STAILQ_FIRST((head)) = (elm); \ +} while (0) + +#define STAILQ_INSERT_TAIL(head, elm, field) do { \ + STAILQ_NEXT((elm), field) = NULL; \ + *(head)->stqh_last = (elm); \ + (head)->stqh_last = &STAILQ_NEXT((elm), field); \ +} while (0) + +#define STAILQ_LAST(head, type, field) \ + (STAILQ_EMPTY((head)) ? \ + NULL : \ + ((struct type *)(void *) \ + ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) + +#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) + +#define STAILQ_REMOVE(head, elm, type, field) do { \ + QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ + if (STAILQ_FIRST((head)) == (elm)) { \ + STAILQ_REMOVE_HEAD((head), field); \ + } \ + else { \ + struct type *curelm = STAILQ_FIRST((head)); \ + while (STAILQ_NEXT(curelm, field) != (elm)) \ + curelm = STAILQ_NEXT(curelm, field); \ + STAILQ_REMOVE_AFTER(head, curelm, field); \ + } \ + TRASHIT(*oldnext); \ +} while (0) + +#define STAILQ_REMOVE_AFTER(head, elm, field) do { \ + if ((STAILQ_NEXT(elm, field) = \ + STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ + (head)->stqh_last = &STAILQ_NEXT((elm), field); \ +} while (0) + +#define STAILQ_REMOVE_HEAD(head, field) do { \ + if ((STAILQ_FIRST((head)) = \ + STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ + (head)->stqh_last = &STAILQ_FIRST((head)); \ +} while (0) + +#define STAILQ_SWAP(head1, head2, type) do { \ + struct type *swap_first = STAILQ_FIRST(head1); \ + struct type **swap_last = (head1)->stqh_last; \ + STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ + (head1)->stqh_last = (head2)->stqh_last; \ + STAILQ_FIRST(head2) = swap_first; \ + (head2)->stqh_last = swap_last; \ + if (STAILQ_EMPTY(head1)) \ + (head1)->stqh_last = &STAILQ_FIRST(head1); \ + if (STAILQ_EMPTY(head2)) \ + (head2)->stqh_last = &STAILQ_FIRST(head2); \ +} while (0) + + +/* + * List declarations. + */ +#define LIST_HEAD(name, type) \ +struct name { \ + struct type *lh_first; /* first element */ \ +} + +#define LIST_HEAD_INITIALIZER(head) \ + { NULL } + +#define LIST_ENTRY(type) \ +struct { \ + struct type *le_next; /* next element */ \ + struct type **le_prev; /* address of previous next element */ \ +} + +/* + * List functions. + */ + +#if (defined(_KERNEL) && defined(INVARIANTS)) +#define QMD_LIST_CHECK_HEAD(head, field) do { \ + if (LIST_FIRST((head)) != NULL && \ + LIST_FIRST((head))->field.le_prev != \ + &LIST_FIRST((head))) \ + panic("Bad list head %p first->prev != head", (head)); \ +} while (0) + +#define QMD_LIST_CHECK_NEXT(elm, field) do { \ + if (LIST_NEXT((elm), field) != NULL && \ + LIST_NEXT((elm), field)->field.le_prev != \ + &((elm)->field.le_next)) \ + panic("Bad link elm %p next->prev != elm", (elm)); \ +} while (0) + +#define QMD_LIST_CHECK_PREV(elm, field) do { \ + if (*(elm)->field.le_prev != (elm)) \ + panic("Bad link elm %p prev->next != elm", (elm)); \ +} while (0) +#else +#define QMD_LIST_CHECK_HEAD(head, field) +#define QMD_LIST_CHECK_NEXT(elm, field) +#define QMD_LIST_CHECK_PREV(elm, field) +#endif /* (_KERNEL && INVARIANTS) */ + +#define LIST_EMPTY(head) ((head)->lh_first == NULL) + +#define LIST_FIRST(head) ((head)->lh_first) + +#define LIST_FOREACH(var, head, field) \ + for ((var) = LIST_FIRST((head)); \ + (var); \ + (var) = LIST_NEXT((var), field)) + +#define LIST_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = LIST_FIRST((head)); \ + (var) && ((tvar) = LIST_NEXT((var), field), 1); \ + (var) = (tvar)) + +#define LIST_INIT(head) do { \ + LIST_FIRST((head)) = NULL; \ +} while (0) + +#define LIST_INSERT_AFTER(listelm, elm, field) do { \ + QMD_LIST_CHECK_NEXT(listelm, field); \ + if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ + LIST_NEXT((listelm), field)->field.le_prev = \ + &LIST_NEXT((elm), field); \ + LIST_NEXT((listelm), field) = (elm); \ + (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ +} while (0) + +#define LIST_INSERT_BEFORE(listelm, elm, field) do { \ + QMD_LIST_CHECK_PREV(listelm, field); \ + (elm)->field.le_prev = (listelm)->field.le_prev; \ + LIST_NEXT((elm), field) = (listelm); \ + *(listelm)->field.le_prev = (elm); \ + (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ +} while (0) + +#define LIST_INSERT_HEAD(head, elm, field) do { \ + QMD_LIST_CHECK_HEAD((head), field); \ + if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ + LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ + LIST_FIRST((head)) = (elm); \ + (elm)->field.le_prev = &LIST_FIRST((head)); \ +} while (0) + +#define LIST_NEXT(elm, field) ((elm)->field.le_next) + +#define LIST_REMOVE(elm, field) do { \ + QMD_SAVELINK(oldnext, (elm)->field.le_next); \ + QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ + QMD_LIST_CHECK_NEXT(elm, field); \ + QMD_LIST_CHECK_PREV(elm, field); \ + if (LIST_NEXT((elm), field) != NULL) \ + LIST_NEXT((elm), field)->field.le_prev = \ + (elm)->field.le_prev; \ + *(elm)->field.le_prev = LIST_NEXT((elm), field); \ + TRASHIT(*oldnext); \ + TRASHIT(*oldprev); \ +} while (0) + +#define LIST_SWAP(head1, head2, type, field) do { \ + struct type *swap_tmp = LIST_FIRST((head1)); \ + LIST_FIRST((head1)) = LIST_FIRST((head2)); \ + LIST_FIRST((head2)) = swap_tmp; \ + if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ + swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ + if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ + swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ +} while (0) + +/* + * Tail queue declarations. + */ +#define TAILQ_HEAD(name, type) \ +struct name { \ + struct type *tqh_first; /* first element */ \ + struct type **tqh_last; /* addr of last next element */ \ + TRACEBUF \ +} + +#define TAILQ_HEAD_INITIALIZER(head) \ + { NULL, &(head).tqh_first } + +#define TAILQ_ENTRY(type) \ +struct { \ + struct type *tqe_next; /* next element */ \ + struct type **tqe_prev; /* address of previous next element */ \ + TRACEBUF \ +} + +/* + * Tail queue functions. + */ +#if (defined(_KERNEL) && defined(INVARIANTS)) +#define QMD_TAILQ_CHECK_HEAD(head, field) do { \ + if (!TAILQ_EMPTY(head) && \ + TAILQ_FIRST((head))->field.tqe_prev != \ + &TAILQ_FIRST((head))) \ + panic("Bad tailq head %p first->prev != head", (head)); \ +} while (0) + +#define QMD_TAILQ_CHECK_TAIL(head, field) do { \ + if (*(head)->tqh_last != NULL) \ + panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ +} while (0) + +#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ + if (TAILQ_NEXT((elm), field) != NULL && \ + TAILQ_NEXT((elm), field)->field.tqe_prev != \ + &((elm)->field.tqe_next)) \ + panic("Bad link elm %p next->prev != elm", (elm)); \ +} while (0) + +#define QMD_TAILQ_CHECK_PREV(elm, field) do { \ + if (*(elm)->field.tqe_prev != (elm)) \ + panic("Bad link elm %p prev->next != elm", (elm)); \ +} while (0) +#else +#define QMD_TAILQ_CHECK_HEAD(head, field) +#define QMD_TAILQ_CHECK_TAIL(head, headname) +#define QMD_TAILQ_CHECK_NEXT(elm, field) +#define QMD_TAILQ_CHECK_PREV(elm, field) +#endif /* (_KERNEL && INVARIANTS) */ + +#define TAILQ_CONCAT(head1, head2, field) do { \ + if (!TAILQ_EMPTY(head2)) { \ + *(head1)->tqh_last = (head2)->tqh_first; \ + (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ + (head1)->tqh_last = (head2)->tqh_last; \ + TAILQ_INIT((head2)); \ + QMD_TRACE_HEAD(head1); \ + QMD_TRACE_HEAD(head2); \ + } \ +} while (0) + +#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) + +#define TAILQ_FIRST(head) ((head)->tqh_first) + +#define TAILQ_FOREACH(var, head, field) \ + for ((var) = TAILQ_FIRST((head)); \ + (var); \ + (var) = TAILQ_NEXT((var), field)) + +#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ + for ((var) = TAILQ_FIRST((head)); \ + (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ + (var) = (tvar)) + +#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ + for ((var) = TAILQ_LAST((head), headname); \ + (var); \ + (var) = TAILQ_PREV((var), headname, field)) + +#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ + for ((var) = TAILQ_LAST((head), headname); \ + (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ + (var) = (tvar)) + +#define TAILQ_INIT(head) do { \ + TAILQ_FIRST((head)) = NULL; \ + (head)->tqh_last = &TAILQ_FIRST((head)); \ + QMD_TRACE_HEAD(head); \ +} while (0) + +#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ + QMD_TAILQ_CHECK_NEXT(listelm, field); \ + if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ + TAILQ_NEXT((elm), field)->field.tqe_prev = \ + &TAILQ_NEXT((elm), field); \ + else { \ + (head)->tqh_last = &TAILQ_NEXT((elm), field); \ + QMD_TRACE_HEAD(head); \ + } \ + TAILQ_NEXT((listelm), field) = (elm); \ + (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ + QMD_TRACE_ELEM(&(elm)->field); \ + QMD_TRACE_ELEM(&listelm->field); \ +} while (0) + +#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ + QMD_TAILQ_CHECK_PREV(listelm, field); \ + (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ + TAILQ_NEXT((elm), field) = (listelm); \ + *(listelm)->field.tqe_prev = (elm); \ + (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ + QMD_TRACE_ELEM(&(elm)->field); \ + QMD_TRACE_ELEM(&listelm->field); \ +} while (0) + +#define TAILQ_INSERT_HEAD(head, elm, field) do { \ + QMD_TAILQ_CHECK_HEAD(head, field); \ + if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ + TAILQ_FIRST((head))->field.tqe_prev = \ + &TAILQ_NEXT((elm), field); \ + else \ + (head)->tqh_last = &TAILQ_NEXT((elm), field); \ + TAILQ_FIRST((head)) = (elm); \ + (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ + QMD_TRACE_HEAD(head); \ + QMD_TRACE_ELEM(&(elm)->field); \ +} while (0) + +#define TAILQ_INSERT_TAIL(head, elm, field) do { \ + QMD_TAILQ_CHECK_TAIL(head, field); \ + TAILQ_NEXT((elm), field) = NULL; \ + (elm)->field.tqe_prev = (head)->tqh_last; \ + *(head)->tqh_last = (elm); \ + (head)->tqh_last = &TAILQ_NEXT((elm), field); \ + QMD_TRACE_HEAD(head); \ + QMD_TRACE_ELEM(&(elm)->field); \ +} while (0) + +#define TAILQ_LAST(head, headname) \ + (*(((struct headname *)((head)->tqh_last))->tqh_last)) + +#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) + +#define TAILQ_PREV(elm, headname, field) \ + (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) + +#define TAILQ_REMOVE(head, elm, field) do { \ + QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ + QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ + QMD_TAILQ_CHECK_NEXT(elm, field); \ + QMD_TAILQ_CHECK_PREV(elm, field); \ + if ((TAILQ_NEXT((elm), field)) != NULL) \ + TAILQ_NEXT((elm), field)->field.tqe_prev = \ + (elm)->field.tqe_prev; \ + else { \ + (head)->tqh_last = (elm)->field.tqe_prev; \ + QMD_TRACE_HEAD(head); \ + } \ + *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ + TRASHIT(*oldnext); \ + TRASHIT(*oldprev); \ + QMD_TRACE_ELEM(&(elm)->field); \ +} while (0) + +#define TAILQ_SWAP(head1, head2, type, field) do { \ + struct type *swap_first = (head1)->tqh_first; \ + struct type **swap_last = (head1)->tqh_last; \ + (head1)->tqh_first = (head2)->tqh_first; \ + (head1)->tqh_last = (head2)->tqh_last; \ + (head2)->tqh_first = swap_first; \ + (head2)->tqh_last = swap_last; \ + if ((swap_first = (head1)->tqh_first) != NULL) \ + swap_first->field.tqe_prev = &(head1)->tqh_first; \ + else \ + (head1)->tqh_last = &(head1)->tqh_first; \ + if ((swap_first = (head2)->tqh_first) != NULL) \ + swap_first->field.tqe_prev = &(head2)->tqh_first; \ + else \ + (head2)->tqh_last = &(head2)->tqh_first; \ +} while (0) + +#endif /* !_SYS_QUEUE_H_ */ |